Note N - Segment Information (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Number of Reportable Segments	2
Revenue from Contract with Customer, Including Assessed Tax	$ 118,876	$ 138,290
Non-US [Member]
Revenue from Contract with Customer, Including Assessed Tax	51,964	71,290
UNITED STATES
Revenue from Contract with Customer, Including Assessed Tax	$ 66,912	$ 67,000
Products Manufactured by NAIE [Member] | Non-US [Member] | Revenue Benchmark [Member] | Product Concentration Risk [Member]
Concentration Risk, Percentage	89.00%	78.00%
Products Manufactured by NAIE [Member] | UNITED STATES
Revenue from Contract with Customer, Including Assessed Tax	$ 0	$ 0